Chapter 2- Structure And Function Of Cells Flashcards
Motor neuron
Located within the CNS that controls the contraction of a muscle or the secretion of a gland
Sensory neuron
Detects changes in the environment and send information about these changes to CNS
Interneuron
A neuron located entirely within the CNS
Central nervous system (CNS)
Brain and spinal cord
Peripheral nervous system (PNS)
Nerves
Soma
Cell body of a neuron which contains the nucleus
Dendrite
A branched, treelike structure attached to the soma of a neuron, received information from the terminal buttons of other neurons
Synapse
A junction between the terminal button of an axon and the membrane of another neuron
Axon
The long, cylindrical structure that conveys information from the soma of a neuron to its terminal buttons
Multipolar neuron
A neuron with one axon and many dendrites attached to its soma
Bipolar neuron
A neuron with one axon and one dendrite attached to its soma
Unipolar neuron
A neuron with one axon attached to its soma, the axon divides, with one branch receiving sensory information and the other sending info to CNS
Terminal button
The bud at the end of a branch of an axon, forms synapses with another neuron, sends information to that neuron
Neurotransmitter
A chemical that is released by a terminal button; has an excitatory or inhibitory effect on another neuron
Membrane
Boundary of the cell; consists of a double layer of lipid molecules
Nucleus
A structure in the central region of a cell; contains nucleolus and chromosomes
Nucleolus
A structure within the nucleus that produces ribosomes
Ribosome
A cytoplasmic structure, made of protein, that serves as the site of production of proteins translated from mRNA
Messenger ribonucleic acid (mRNA)
A macromolecule that delivers genetic information concerning the synthesis of a protein from a portion of a chromosome to a ribosome
Enzyme
A molecule that controls a chemical reaction, combining two substances or breaking a substance into two parts.
Mitochondrion
An organelle that is responsible for extracting energy from nutrients
Golgi apparatus
A complex of parallel membranes in the cytoplasm that wraps the products of the secretory cell
Exocystosis
The secretion of a substance by a cell through means of vesicles; the process by which neurotransmitters are secreted
Lysosomes
Organelles surrounded by membrane; contains enzymes that break down waste products
Microtubule
A long strand of protein filaments arranged around a hollow core; involved in transporting substances from place to place within the cell
Axoplasmic transport
An active process by which substances are propelled along mixrotubules that run the length of the axon
Anterograde
In a direction along an axon from the cell body toward terminal buttons
Retrograde
In a direction along an axon from the terminal buttons toward cell body
Glia
The supporting cells of the central nervous system (astrocytes, oligodendrocytes, microglia)
Astrocytes
Glial cell- provides nutrients and other substances and regulates the chemical composition of the extracellular fluid
Phagocytosis
The process by which cells engulf and digest other cells or debris caused by cellular degeneration
Oligodendrocyte
Glial cell that forms myelin sheaths
Myelin sheath
A sheath that surrounds axons and insulates them, preventing messages from spreading between adjacent axons
Node of ranvier
A naked portion of a myelinated axon between adjacent oligodendroglia or Schwann cells